Marco: A related question came up a few years’ ago and here are my thoughts on the situation – What needs to be looked at here are the basic hydraulics equations that HEC-RAS solves and figure out what needs to be changed for a different gravity environment. First, the rotational speed of the system can be ignored as that does not get into the equations that we are solving. Second, how does the gravitational acceleration and atmospheric pressure enter the computations? RAS solves the 1 and 2-D steady/unsteady flow equations for open channel flow. By “open channel” we mean that there is a liquid surface below an atmosphere. Included in these equations (St. Venant equations) is gravitational acceleration; which in the RAS software is defaulted to Earth’s (32.2 ft/sec2). Also built into these equations is the unit weight of water here (62.4 lb/ft3). The boundary friction in these equations is empirically based – so that external force would need to be researched and translated. There are different methods used in Europe and the U.S. for describing boundary friction and other energy losses. So, at the center of the model are some equations that are not dimensionless and contain local (Earth) parameters as well as empirical coefficients. (See “Open Channel Hydraulics”, by Richard H. French – 1985 for background on the governing equations.) I think that what you are interested in is certainly doable and will be a valuable next step in figuring out what is happening there. Once the hydraulic equations are appropriately modified and tested, you can start to look at the sediment transport activities there.
Michael